5 research outputs found
Condensate fluctuations of a trapped, ideal Bose gas
For a non-self-interacting Bose gas with a fixed, large number of particles
confined to a trap, as the ground state occupation becomes macroscopic, the
condensate number fluctuations remain micrscopic. However, this is the only
significant aspect in which the grand canonical description differs from
canonical or microcanonical in the thermodynamic limit. General arguments and
estimates including some vanishingly small quantities are compared to explicit,
fixed-number calculations for 10^2 to 10^6 particles.Comment: 16 pages (REVTeX) plus 4 figures (ps), revision includes brief
comparison of repulsive-interaction vs. fixed-N fluctuation damping. To be
published in Phys. Rev.
Thermodynamics of Coupled Identical Oscillators within the Path Integral Formalism
A generalization of symmetrized density matrices in combination with the
technique of generating functions allows to calculate the partition function of
identical particles in a parabolic confining well. Harmonic two-body
interactions (repulsive or attractive) are taken into account. Also the
influence of a homogeneous magnetic field, introducing anisotropy in the model,
is examined. Although the theory is developed for fermions and bosons, special
attention is payed to the thermodynamic properties of bosons and their
condensation.Comment: 13 REVTEX pages + 9 postscript figure
Confined Harmonically Interacting Spin-Polarized Fermions in a Magnetic Field: Thermodynamics
We investigate the combined influence of a magnetic field and a harmonic
interparticle interaction on the thermodynamic properties of a finite number of
spin polarized fermions in a confiment potential. This study is an extension
using our path integral approach of symmetrized density matrices for identical
particles. The thermodynamical properties are calculated for a three
dimensional model of N harmonically interacting spin polarized fermions in a
parabolic potential well in the presence of a magnetic field. The free energy
and the internal energy are obtained for a limited number of particles.
Deviations from the thermodynamical limit become negligible for about 100 or
more particles, but even for a smaller number of fermions present in the well,
scaling relations similar to those of the continuum approximation to the
density of states are already satisfied.Comment: 7 pages REVTEX and 8 postscript figures, accepted in Phys. Rev.